This invention relates to a spool on which a web material, such as photographic film, can be wound. More particularly, the invention relates to such a spool in which the full width of the end portion of the film or other web material is attached to the spool core and the film extends tangentially from the spool core.
Various techniques have been used to attach the end of a strip of film or other web material to a spool. For example, a film end can be attached to a spool by means of a piece of adhesive tape. Also, the end portion of the film can have one or more openings therein and can be inserted into a slot that extends through a spool. Such a spool has one or more teeth or hooks in the slot for engaging the film strip through the openings. Clips have also been used for attaching webs of various kinds to a spool core. After the end of the web is attached to the spool, the spool is rotated to wind a predetermined length of the web onto the spool. Ordinarily removal of the web from the spool is accomplished by pulling the end of the web opposite from its attachment to the spool away from the spool. More specifically, the free end of the web can project through a slot in a cassette where it is engaged by a mechanism in a camera or film processor for withdrawing film from the cassette. However, in some instances it is desired to drive the film out of a cassette by rotating the film spool within the cassette. In order to thrust the film out of the cassette in this manner, a force must be exerted on the film in its lengthwise direction. If the film is attached by conventional methods, such as an adhesive tape or by inserting a film end into a slot and engaging it with hooks in the slot, there is not sufficient rigidity or beam strength to effect thrusting of the free end of the film out of the cassette.